<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        div{
            width: 1000px;
            height: 200px;
            background-color: skyblue;
            margin: 50px;
            /* 外边距不会撑大盒子 */
            /* margin多值写法和padding一样 */
        }
    </style>
</head>
<body>
    <div>
        test
    </div>
</body>
</html>